1. Field of the Invention
The present invention relates to a head suspension for a hard disk drive installed in an information processing apparatus such as a computer.
2. Description of Related Art
A hard disk drive (HDD) employs a head suspension for suspending a magnetic head to write and read data to and from a magnetic disk. To transfer write and read signals to and from the magnetic head, wires are connected to the magnetic head. The wires are arranged on an insulating base layer that is made of flexible resin and is formed on a flexure. The flexure is a part of the head suspension and is made of a resilient stainless-steel thin plate. The wires are covered with an insulating cover layer made of flexible resin.
When the flexure is assembled into the head suspension, the surface of the insulating cover layer may be rubbed with another part such as a clamp or a tool, to accumulate static electricity. This static electricity is transferred to the wires under the insulating cover layer. If the magnetic head of the head suspension touches a tool or a jig, the static electricity accumulated in the wires will move to the magnetic head to deteriorate or destroy a read element of the magnetic head.
Recent hard disk drives employ highly sensitive read elements such as MR (magnetoresistive) elements, GMR (giant magnetoresistive) elements, and TuMR (tunneling magnetoresistive) elements. These elements are vulnerable to static electricity and require an electrostatic discharge (ESD) damage preventive measure.
One measure for preventing the electrostatic discharge damage is to employ an ionizer (static electricity remover). The ionizer needs specific facilities and an additional process, to thereby increase costs, as disclosed in Japanese Unexamined Patent Application Publication No. 9-282624 and in Shoji Natori (Hitachi Computer Equipment) “ESD assessment of GMR head,” Jan. 31, 2003, Technical Committee, ESD Control Group.